Bogus Prostate/Omega-3 Study Takes Another Hit

New discovery further undermines the headline-making but misleading conclusions of 2013 study

Jo-Carolyn Goode | 3/24/2015, 7:56 a.m.
Do seafood-source omega-3s help protect against prostate cancer? Most of the published studies suggest that omega-3s tend to curb the ...

Do seafood-source omega-3s help protect against prostate cancer?

Most of the published studies suggest that omega-3s tend to curb the growth of prostate tumors.

For example, see Positive Omega-3/Prostate Trial, and the links it contains.

But in 2013, publication of a scientifically dubious study caused some men to stop taking omega-3 fish oil supplements (see Fishy Prostate News).

For that study, Ohio State University researchers analyzed data from the Selenium and Vitamin E Cancer Prevention Trial or SELECT (Brasky TM et al. 2013).

Their analysis showed that the men with the highest blood levels of seafood-source omega-3s were more likely to develop prostate cancer.

But experts dismissed those conclusions, because, among other reasons, the Ohio State team failed to properly account for major risk factors.

(Its other flaws are covered in the “Seven reasons for deep skepticism” section of our Fishy Prostate News article).

As prostate-cancer expert Professor Anthony D'Amico, M.D., of Harvard Medical School said in an interview, “… they left out some very important risk factors ... [which] makes this association extremely weak and possibly false.”

And, soon after the Ohio State paper caused undue concern, more evidence appeared suggesting that omega-3s can help curb prostate cancer: see Omega-3 Diet Reduced Prostate Risk Factors and Omega-3 Curbed Prostate Cancer Growth.

Studies have revealed several ways in which omega-3s should discourage cancer growth ... and a recent study found they possess a previously unknown prostate-protective property (Galet C et al. 2013).

Now, researchers have found yet another way in which omega-3s may curb the growth and spread of prostate cancer.

Study finds omega-3s may inhibit prostate cancer by a novel method

The new lab study was led by Professor Kathryn Meier, Ph.D., from the Washington State University College of Pharmacy (Liu Z et al. 2015).

Working with prostate cell cultures, Meier and two students found that omega-3 fatty acids bind to a cell-surface receptor called FFA4 (free fatty acid receptor 4).

The FFA4 receptor acts as a signal to inhibit tumor growth factors, thereby slowing the progression of prostate cancer.

“This kind of knowledge could lead us to better treat or prevent cancer," Meier said.

It’s yet to be proven that fish or omega-3 fish oils can produce and maintain this specific anti-cancer effect in people.

And, the WSU study suggests that stimulation of the FFA4 receptor must be continuous ... while the effect of dietary omega-3s (from fish or fish oil) on the receptor may fade after they're fully metabolized.

So it seems urgent to discover whether consuming fish or omega-3 fish oil daily might affect the receptor enough to help curb cancer in people.

Most prostate cancers grow very slowly ... so any food factors that can help slow tumor growth could make a big difference to rates of diagnosis and death.

Sources

Aronson WJ, Barnard RJ, Freedland SJ, Henning S, Elashoff D, Jardack PM, Cohen P, Heber D, Kobayashi N. Growth inhibitory effect of low fat diet on prostate cancer cells: results of a prospective, randomized dietary intervention trial in men with prostate cancer. J Urol. 2010 Jan;183(1):345-50. doi: 10.1016/j.juro.2009.08.104. Epub.